E46 Touring: why do lights move up and down on switch-on?
Discussion
Wrong!
Non-xenon lights are not self levelling, they don't have to be as they're not as bright and therefore less risk of blinding other vehicles. I believe it's a legal requirement that Xenons are self -levelling.
As for why your head lights move down and up when you switch the ignition on; well that because the light module asks the headlight aim motors (the ones that change the headlight load position via that knurled wheel)to carry out a reference run to their top and bottom mechanical limits. If either of the motors does not acheive this then the light module detects it and stores a DTC in the error memory. It's a self check function to ensure that a broken motor doesn't go undetected causing incorrect beam pattern.
Non-xenon lights are not self levelling, they don't have to be as they're not as bright and therefore less risk of blinding other vehicles. I believe it's a legal requirement that Xenons are self -levelling.
As for why your head lights move down and up when you switch the ignition on; well that because the light module asks the headlight aim motors (the ones that change the headlight load position via that knurled wheel)to carry out a reference run to their top and bottom mechanical limits. If either of the motors does not acheive this then the light module detects it and stores a DTC in the error memory. It's a self check function to ensure that a broken motor doesn't go undetected causing incorrect beam pattern.
Edited by T-bagger on Wednesday 27th January 00:08
T-bagger said:
Wrong!
Non-xenon lights are not self levelling, they don't have to be as they're not as bright and therefore less risk of blinding other vehicles. I believe it's a legal requirement that Xenons are self -levelling.
As for why your head lights move down and up when you switch the ignition on; well that because the light module asks the headlight aim motors (the ones that change the headlight load position via that knurled wheel)to carry out a reference run to their top and bottom mechanical limits. If either of the motors does not acheive this then the light module detects it and stores a DTC in the error memory. It's a self check function to ensure that a broken motor doesn't go undetected causing incorrect beam pattern.
Non-xenon lights are not self levelling, they don't have to be as they're not as bright and therefore less risk of blinding other vehicles. I believe it's a legal requirement that Xenons are self -levelling.
As for why your head lights move down and up when you switch the ignition on; well that because the light module asks the headlight aim motors (the ones that change the headlight load position via that knurled wheel)to carry out a reference run to their top and bottom mechanical limits. If either of the motors does not acheive this then the light module detects it and stores a DTC in the error memory. It's a self check function to ensure that a broken motor doesn't go undetected causing incorrect beam pattern.
Edited by T-bagger on Wednesday 27th January 00:08
T-bagger said:
Wrong!
Non-xenon lights are not self levelling, they don't have to be as they're not as bright and therefore less risk of blinding other vehicles. I believe it's a legal requirement that Xenons are self -levelling.
As for why your head lights move down and up when you switch the ignition on; well that because the light module asks the headlight aim motors (the ones that change the headlight load position via that knurled wheel)to carry out a reference run to their top and bottom mechanical limits. If either of the motors does not acheive this then the light module detects it and stores a DTC in the error memory. It's a self check function to ensure that a broken motor doesn't go undetected causing incorrect beam pattern.
A true, quality answer!Non-xenon lights are not self levelling, they don't have to be as they're not as bright and therefore less risk of blinding other vehicles. I believe it's a legal requirement that Xenons are self -levelling.
As for why your head lights move down and up when you switch the ignition on; well that because the light module asks the headlight aim motors (the ones that change the headlight load position via that knurled wheel)to carry out a reference run to their top and bottom mechanical limits. If either of the motors does not acheive this then the light module detects it and stores a DTC in the error memory. It's a self check function to ensure that a broken motor doesn't go undetected causing incorrect beam pattern.
Thank you!
T-bagger said:
Wrong!
Non-xenon lights are not self levelling, they don't have to be as they're not as bright and therefore less risk of blinding other vehicles. I believe it's a legal requirement that Xenons are self -levelling.
As for why your head lights move down and up when you switch the ignition on; well that because the light module asks the headlight aim motors (the ones that change the headlight load position via that knurled wheel)to carry out a reference run to their top and bottom mechanical limits. If either of the motors does not acheive this then the light module detects it and stores a DTC in the error memory. It's a self check function to ensure that a broken motor doesn't go undetected causing incorrect beam pattern.
Excellent post - answers a question I have had for about 4 years now Non-xenon lights are not self levelling, they don't have to be as they're not as bright and therefore less risk of blinding other vehicles. I believe it's a legal requirement that Xenons are self -levelling.
As for why your head lights move down and up when you switch the ignition on; well that because the light module asks the headlight aim motors (the ones that change the headlight load position via that knurled wheel)to carry out a reference run to their top and bottom mechanical limits. If either of the motors does not acheive this then the light module detects it and stores a DTC in the error memory. It's a self check function to ensure that a broken motor doesn't go undetected causing incorrect beam pattern.
Edited by T-bagger on Wednesday 27th January 00:08
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